The reason that bar codes are business friendly is that bar code scanners are, compared to the 1970’s, relatively low cost.
Most importantly, they are extremely accurate – Only about 1 in 100,000 entries will be wrong.
This equates to a figure of 0.001%
Bar Code Scanning
Code 39 (also known as "Code 3 of 9")
Is a barcode symbology that can encode uppercase letters (A to Z), digits (0 to 9) and a handful of special characters like the American $ sign.
The barcode itself does not contain a check digit (in contrast to the Code 128), but it is considered self-checking on the grounds that a single
erroneously interpreted bar cannot generate another valid character.
The most serious drawback of Code 39 is its low data density:
It requires more space to encode data in Code 39 than, for example, in Code 128.
This means that very small goods cannot be labeled with a Code 39 based barcode. However, Code 39 is still widely used and can be decoded with virtually any barcode reader.
Bar Code Scanning
Code 128
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is a very high-density barcode symbology, used extensively world wide in shipping and packaging industries.•
It is used for alphanumeric or numeric-only barcodes.•
It can encode all 128 characters of ASCII coding and is also capable of encoding two numbers into one character width, called double density.Bar Code Scanning
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This feature is evidence of it being designed to reduce the amount of space the bar code occupies, to address the ever-increasing needs of item catalogs.•
Each printed character can have one of three different meanings, depending on which of three different character sets are employed.•
Code 128 is the major component of the labeling standard for GS1-128 (formerly known as UCC/EAN-128), used as product identification for container and pallet levels of retail markets.Bar Code Scanning
Interleaved 2 of 5
Is a continuous two-width barcode symbology encoding digits.
I2/5 encodes pairs of digits; the first digit is encoded in the five bars (the "black lines"), while the second digit is encoded in the five
spaces interleaved with them (the "white lines").
Before the actual pairs there is a start code consisting of 4 narrow lines, and after all symbols there is the stop code consisting of 1 wide line followed by 3 narrow lines.
Bar Code Scanning
As only an even number of digits can be encoded, a 0 is added as first digit. Sometimes an odd number of digits is encoded by putting five narrow spaces in the last pair.
A checksum can be added as last digit, which is calculated in the same way as UPC checksums.
There are very specific constraints on the height and width of the bars and the width of the "quiet areas", the blank areas before the start and after the stop symbol.
Bar Code Scanning
PDF417 is a stacked linear bar code symbol used in a variety of applications, primarily transport, identification cards, and inventory management.
PDF stands for Portable Data File.
The PDF417 format was developed by Symbol Technologies, now part of the Motorola group.
Bar Code Scanning
A Data Matrix code is a two-dimensional matrix barcode consisting of black and white square modules arranged in either a square or rectangular pattern.
The information to be encoded can be text or raw data. Usual data size is from a few bytes up to 2 kilobytes.
The length of the encoded data depends on the symbol dimension used.
Error correction codes are added to increase symbol strength: even if they are partially damaged, they can still typically be read.
A Data Matrix symbol can store up to 2,335 alpha - numeric characters.
Bar Code Scanning
The most popular application for Data Matrix is marking small items, due to the code’s ability to encode fifty characters in a symbol that is readable at a size of 2 or 3 mm2 and the fact that the code can be read with only a 20% contrast ratio.
The Electronic Industries Alliance (EIA) recommends using Data Matrix for labeling small electronic components.
Data Matrix codes are part of a new traceability drive in many
industries, particularly the aerospace industry where quality control is tight and a black market exists for counterfeit or non-serviceable parts.
Bar Code Scanning
Data Matrix codes (and the accompanying alpha-numeric data) identify details of the component, including manufacturer ID, part number and a unique serial number.
The United States Department of Defense aims to have all
components of every new aircraft identified by Data Matrix codes.
Data Matrix forms the basis of the Direct Part Marking (DPM) projects currently under way by parts manufacturers, etc.
Bar Code Scanning
Direct Part Marking (DPM)
Is a process to permanently mark parts with a barcode.
It is done to allow the tracking of parts through their full life cycle.
But, the interpretation of 'permanent' often depends on the context the part is used.
In the aerospace industry an aircraft part may be in service for over 30 years. Within telecom and computer industries the life cycle may only last a few years.
Bar Code Scanning
DPM is often used by automotive, aerospace, and electronic manufacturers to facilitate a reliable identification of their parts.
This can assist in data logging for safety, for warranty issues and to satisfy regulatory requirements.
Also the United States Department of Defense demands a physical mark on tangible assets in conjunction with the Item Unique
Identification.
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Methods to produce a permanent mark on parts are:
Casting or moulding into the material Dot peen
Stencil (mechanical cut, photo process, laser cut) Embroidery
Bar Code Scanning
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Non-intrusive marking methods are recommended for parts used in safety critical applications.•
It is more difficult to place a Data Matrix on a curved surface than it is on a flat surface.•
Highly polished metal surfaces should be textured to reduce glare prior to marking. The textured area should extend one symbol width beyond the borders of marking.•
When a 2D Symbol is used, the size of the part is not a relevant factor as the available marking area is reduced to below 1/4 inch squareBar Code Scanning
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The operating environment should be controlled, the marking method should survive in its intended environment and remain readable for the life cycle of the part.•
A rough surface is not suitable for a 2D barcode as the dataelements can be recognized appropriately. The surface roughness levels should be limited to 8 micro-inches.
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Surface thickness must be taken into account when applyingintrusive markings to prevent deformation or excessive weakening of the part. In most applications the marking depth should not exceed 1/10 the thickness of the part.
Bar Code Scanning
So,
How do we actually do this?
Bar Code Scanning
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Barcode Scanners and image based data capture devices (inc DPM & UV).Typically, these will be connected by BT (Bluetooth) nowadays, to a base station, or by a direct cable to the controlling PC.
Bar Code Scanning
Rugged mobile computers.
Again, these will use a BT connection or a cable connection.
Bar Code Scanning
Because of the design of the hardware, these will typically use a cabled connection to the host serving the scanner.
Production line scanning:
Bar Code Scanning
Mobile / Hand Held Data Terminals.
Whereas here, the device has the scanning ability built in, and it also has the network connectivity to send the data to the host device.
Bar Code Scanning
And how do we get the items labelled?
Basically, it depends finally on what the application /device / product that is required to be labelled.
Bar Code Scanning
If the product is smooth, flat, clean, dry, etc, then a self adhesive label can be applied.
This can be paper based, it can be paper based using thermal paper, it can be manufactured on plastic, it can even be produced using foam ‘tape’.
It can also be printed onto a plastic tag and then affixed to the product, using a cable (zip) tie if the product is to be shipped as a bundle of the product.
Bar Code Scanning
Depending on the technology to be used for the actual label, the printing media may also be in use already ……
Bar Code Scanning
For any information on Bar Code Scanning, Scanning Applications, or Labelling, please call Spirit Data Capture Ltd:
Telephone: 0845 337 3242
URL: www.spiritdatacapture.co.uk
E-mail: [email protected]
Fax: 0870 762 2824
Spirit Data Capture can also supply the hardware required for you to Bar Code your products.